CN116104441A

CN116104441A - Permanent expansion type open hole packer

Info

Publication number: CN116104441A
Application number: CN202111324876.8A
Authority: CN
Inventors: 廖洪千; 陈武君; 胡亮; 杨德锴; 李夯; 刘阳
Original assignee: China Petroleum and Chemical Corp; Sinopec Research Institute of Petroleum Engineering
Current assignee: China Petroleum and Chemical Corp; Sinopec Research Institute of Petroleum Engineering
Priority date: 2021-11-10
Filing date: 2021-11-10
Publication date: 2023-05-12

Abstract

The invention provides a permanent expansion type open hole packer, which comprises an outer cylinder body and an inner cylinder body which are sleeved together, wherein the outer cylinder body is provided with an inner cavity, and a first channel is defined in the inner cylinder body; the piston cavity is arranged between the outer cylinder body and the inner cylinder body, a first piston is arranged in the piston cavity, a liquid inlet hole which is communicated with the first channel and the piston cavity is formed in the outer wall of the inner cylinder body, and a rubber cylinder which is communicated with the inner cavity is arranged on the outer cylinder body at one end of the piston, which is far away from the liquid inlet hole. The first piston is provided with a liquid injection channel capable of communicating the rubber cylinder and the liquid inlet, and the first piston can move in the piston cavity under the action of fluid pressure in the first channel, so that the first piston can move from a first position for cutting off communication between the rubber cylinder and the liquid inlet to a second position for keeping the rubber cylinder and the liquid inlet smooth, and fluid in the first channel flows into the rubber cylinder to realize rubber cylinder setting.

Description

Permanent expansion type open hole packer

Technical Field

The invention relates to the field of oilfield development, in particular to a permanent expansion type open hole packer.

Background

In the petroleum exploitation process, an open hole staged fracturing technology is one of common technologies. The technology can improve the single well yield and is one of effective processes for realizing single well up-production. In the open hole staged fracturing process, the packer is one of the most commonly used downhole equipment and is mainly divided into a compression open hole packer and an expansion packer.

Compared with a compression type open hole packer, the expansion type packer has the advantages of larger expansion ratio, longer sealing section, stronger irregular adaptability of the borehole and larger advantage in open hole layering. To avoid premature inflation of the packer and to achieve effective inter-layer separation, the injection valve must achieve both opening and closing functions. Meanwhile, the secondary expansion sealing of the rubber cylinder is required to be prevented, so that the sealing performance and reliability of the packer are ensured.

Disclosure of Invention

Aiming at the technical problems, the invention aims to provide a permanent expansion type open hole packer. The permanent expansion type open hole packer can avoid the advanced expansion of the packer, realize effective interlayer separation and prevent the secondary expansion of the packing element.

According to the present invention there is provided a permanently expanded open hole packer comprising: the device comprises an outer cylinder body and an inner cylinder body which are sleeved together, wherein the outer cylinder body is provided with an inner cavity, and a first channel for fluid circulation is defined in the inner cylinder body; the piston cavity is arranged between the outer cylinder body and the inner cylinder body, a first piston is arranged in the piston cavity, a liquid inlet hole which is communicated with the first channel and the piston cavity is formed in the outer wall of the inner cylinder body, and a rubber cylinder which is communicated with the inner cavity is arranged on the outer cylinder body at one end of the piston, which is far away from the liquid inlet hole.

The first piston is provided with a liquid injection channel which can be communicated with the inner cavity of the rubber cylinder and the liquid inlet hole, and the first piston can move in the piston cavity under the action of fluid pressure in the first channel, so that the first piston can move from a first position for cutting off the communication between the inner cavity of the rubber cylinder and the liquid inlet hole to a second position for keeping the rubber cylinder and the liquid inlet hole unblocked, and fluid in the first channel flows into the rubber cylinder to realize rubber cylinder setting.

In a preferred embodiment, the filling channel is configured in a general L shape, and has a liquid inlet section arranged along the axial direction of the outer cylinder body and a liquid outlet section arranged along the radial direction of the outer cylinder body, wherein the liquid inlet section and the liquid outlet section can be respectively communicated with the liquid inlet hole and the inner cavity of the rubber cylinder.

In a preferred embodiment, a first step is provided on the inner wall of the piston chamber, the first step dividing the piston chamber into a small diameter chamber having a smaller diameter and a large diameter chamber having a larger diameter, the chamber diameter of the small diameter chamber being set equal to the diameter of the first piston.

The position of the first step part is set in such a way that when the first piston is in the first position, the liquid inlet section and the liquid outlet section of the liquid injection channel are simultaneously positioned in the small-diameter cavity, and when the first piston is in the second position, the liquid inlet section and the liquid outlet section of the liquid injection channel are respectively positioned in the small-diameter cavity and the large-diameter cavity of the piston cavity.

In a preferred embodiment, the permanently expanded open hole packer further comprises a pressure relief assembly capable of relieving fluid pressure in the first passageway to which the first piston is subjected after the packing element is set, such that the first piston moves from the second position in a direction toward the first position.

In a preferred embodiment, the pressure relief assembly includes a second piston disposed within the piston chamber and a pressure relief aperture extending through the outer cylinder to communicate the piston chamber with a space outside the outer cylinder.

Wherein a first gap communicating with the liquid inlet is formed between the second piston and the first piston, and the second piston is capable of moving within the piston cavity under the action of fluid pressure in the first channel, so that the second piston has a third position in which communication between the pressure relief hole and the liquid inlet is cut off, and a fourth position in which the liquid inlet and the pressure relief hole remain in communication.

In a preferred embodiment, the first and second pistons are fixed in the piston chamber by first and second shear pins, respectively, the shear force of the second shear pin being set to be greater than the shear force of the first shear pin.

In a preferred embodiment, a first clamping spring is further arranged on the first piston, and the first clamping spring can fix the first piston at a fifth position for cutting off communication between the liquid inlet hole and the seat hole after the rubber cylinder is set.

In a preferred embodiment, a second gap is arranged between the second piston and the side wall of the piston cavity, an elastic piece is arranged in the gap, the second piston is connected with the side wall of the piston cavity through the elastic piece, and the elastic piece can push the second piston to move to a sixth position for cutting off communication between the pressure release hole and the liquid inlet hole when the first piston is in a fifth position.

In a preferred embodiment, the permanently expanded open hole packer further comprises a second clamp spring, which is capable of securing the second piston in the sixth position.

In a preferred embodiment, a balance hole is further provided on the outer wall of the outer cylinder to communicate the second gap with the outer space of the outer cylinder.

In a preferred embodiment, a step is further provided on the outer wall of the inner cylinder of the first piston, which is remote from the inlet opening.

Drawings

The present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a schematic diagram of a permanently expanded open hole packer in accordance with one embodiment of the invention.

FIG. 2 is a schematic illustration of the permanently expanded open hole packer of FIG. 1 in a fluid-filled set condition.

In this application, all of the figures are schematic drawings which are intended to illustrate the principles of the invention and are not to scale.

Detailed Description

The invention is described below with reference to the accompanying drawings. In this context, the terms "left side" and "right side" refer to the side closer to the upper joint and the side further from the upper joint, respectively.

The operation of the permanently expanded open hole packer 100 according to the present invention is briefly described below.

FIG. 1 shows a permanently expanded open hole packer 100 according to one embodiment of the invention. As shown in fig. 1, the permanently expanded open hole packer 100 includes an outer sleeve 10 with an upper joint 12 disposed at a first end 11 of the outer sleeve 10. At the same time, an inner cavity 15 is defined in the outer sleeve 10, an inner sleeve 20 is arranged in the inner cavity 15, and a first passage 25 for downhole fluid communication is defined in the inner sleeve 20.

As shown in fig. 1, a piston chamber 30 is provided between the outer sleeve 10 and the inner sleeve 20 in a radial direction, a first piston 35 is provided in the piston chamber 30, and the first piston 35 is capable of moving in an axial direction in the piston chamber 30 under an external force.

At the same time, a pressure relief assembly 1 is also provided in the piston chamber 30. The pressure relief assembly 1 includes a second piston 38 disposed within the piston chamber 30. A first gap 36 is provided between the second piston 38 and the first piston 35 in the axial direction. A liquid inlet 32 is further provided on the outer wall of the inner cylinder 20, and the liquid inlet 32 is communicated with the first gap 36.

As shown in fig. 1, at least one first shear pin 351 and at least one second shear pin 381 are further provided on the inner wall of the outer cylinder 10, respectively. The first and

second pistons

35 and 38 are fixed to the outer cylinder by first and

second shear pins

351 and 381, respectively.

In the present invention, a liquid injection passage 16 is also provided in the first piston 38. The liquid injection passage 16 is configured in a substantially "L" shape such that the liquid injection passage 16 has a liquid inlet section 161 arranged in the axial direction of the outer cylinder 10 and a liquid outlet section 162 arranged in the radial direction of the outer cylinder 10. Wherein the liquid inlet section 161 is located at one side of the first piston 35 close to the liquid inlet hole 32.

Meanwhile, a first step 18 is also provided on the inner wall of the piston chamber 30. The first step 18 can divide the piston chamber 30 into a small diameter chamber 181 having a smaller diameter and a large diameter chamber 182 having a larger diameter. And, the cavity diameter of the small diameter cavity 181 is set to be equal to the outer diameter of the first piston 35.

In addition, a rubber cylinder (not shown) is disposed on the outer cylinder body at the end of the piston away from the liquid inlet, and the inner cavity of the rubber cylinder is communicated with the large-diameter cavity 182 of the piston cavity 30.

As shown in fig. 1, when the permanently expanded open hole packer 100 is in the initial state, the liquid inlet section 161 and the liquid outlet section 162 of the liquid injection channel 16 are simultaneously located in the small-diameter cavity 181. At this time, since the diameter of the small-diameter cavity 181 is equal to the diameter of the first piston 35, the inner wall of the small-diameter cavity 181 can cover the liquid discharge section 162 of the liquid injection passage 16, and the fluid in the liquid injection passage 16 is prevented from flowing out of the liquid discharge section 162. At this time, the first piston 35 is located at a first position capable of cutting off communication between the packing element and the liquid inlet 32.

As shown in fig. 1, a pressure relief hole 19 penetrating the outer wall of the outer cylinder 10 is further provided on the outer wall of the outer cylinder 10 corresponding to the second piston 38. When the permanently expanded open hole packer 100 is in the initial state, two ends of the second piston 38 are respectively located at two axial sides of the pressure release hole 19, so that the second piston 38 can cut off the communication between the liquid inlet hole 32 and the pressure release hole 19. At this time, the second piston 38 is located at a third position that cuts off communication between the relief hole 19 and the intake hole 32.

In summary, when the permanently expandable open hole packer 100 is in the initial state, the first piston 35 can cut off the communication between the seat hole 16 and the inner cavity of the packing element and the liquid inlet 32, thereby preventing the packing element from being set forward.

When the high-pressure fluid is injected into the first passage 25, the high-pressure fluid in the first passage 25 flows into the first gap 36 first, thereby exerting a force on the first piston 35 and the second piston 38 in a direction away from the liquid inlet 32 at the same time.

FIG. 2 is a schematic illustration of the permanently expanded open hole packer 100 of FIG. 1 in a fluid-filled set condition. As shown in fig. 2, in the present invention, the shearing force of the second shearing pin 381 is set to be greater than that of the first shearing pin 351. Thus, when the high pressure fluid in the first passage 25 flows into the first gap 36, the first shear pin 351 is sheared first. Subsequently, the first piston 35 is moved away from the inlet 32 by the high-pressure fluid until the drain 162 of the filling channel 16 passes through the first step 18 and reaches the large diameter cavity 182 of the piston cavity 30.

At this time, since the diameter of the large diameter cavity 182 is larger than the diameter of the first piston 35, the piston cavity 30 cannot close the liquid inlet channel 16. Subsequently, the high-pressure fluid in the first channel 25 can enter the rubber cylinder through the liquid inlet hole 32, the liquid inlet channel 16 and the large-diameter cavity 182 in sequence, so as to support the rubber cylinder to expand to complete setting. At this time, the first piston 35 is in a second position for keeping the rubber cylinder and the liquid inlet 32 in communication.

As shown in fig. 2, a second step portion 26 is further disposed on the outer wall of the inner cylinder 20 of the first piston 35, which is far from the liquid inlet 32. The first piston 35 can form engagement with the second stepped portion 26 when it moves to the second position, so that the first piston 35 cannot move further rightward.

When the packing element is set, the volume of the packing element is not increased, and the high-pressure fluid in the first channel 25 cannot enter the packing element after reaching the first gap 36. The pressure in the first gap 36 then continues to rise until this pressure shears the second shear pin 381.

When the second shear pin 381 is sheared, the second piston 38 will move to the left under the force of the fluid pressure in the first gap 36 until the entire second piston 38 moves to the left of the relief hole 19. At this time, the relief hole 19 and the intake hole 32 are in communication, and the second piston 38 reaches a fourth position where the intake hole 32 and the relief hole 19 are in communication.

When the liquid inlet 32 and the pressure release hole 19 are communicated, the high-pressure fluid in the first channel 25 can sequentially pass through the liquid inlet 32 and the pressure release hole 19 to reach the space outside the outer cylinder 10. At this time, the pressure in the first gap 36 is rapidly decreased until the pressures on the left and right sides of the second piston 38 are balanced.

As the pressure in the first gap 36 decreases, the pressure on the right side of the first piston 35 will be higher than the pressure on the left side again, and under the action of this pressure difference, the first piston 35 will move to the left again until the drain 162 of the liquid inlet channel 16 enters the small diameter cavity 181 of the piston cavity 30. At this time, the first piston 35 re-cuts off the communication between the liquid inlet hole 32 and the seat hole 16, and the first piston 35 moves to a fifth position in which the communication between the liquid inlet hole 32 and the seat hole 16 is re-cut off.

As shown in fig. 2, a first snap spring 355 is further provided on the first piston 35. The first clamping spring 355 can be configured, for example, as a clamping spring. The first clamp spring 355 can fix the first piston 35 in the fifth position after the first piston 35 reaches the fifth position, and prevent the first piston 35 from moving further in the axial direction.

As shown in fig. 2, a second gap 384 is also provided between the second piston 38 and the side wall of the piston chamber 30. A spring 386 is disposed within the second gap 384, the spring 386 being, for example, a spring, and the second piston 38 being coupled to a side wall of the piston chamber 30 by the spring 386. The spring 386 is disposed in compression when the second piston 38 reaches the fourth position.

When the first piston 35 reaches the fifth position, the communication between the liquid inlet 32 and the seat hole 16 is cut off, and the fluid in the first passage 25 can be normally discharged through the pressure release hole 19, so that the fluid pressures on the left and right sides of the second piston 38 are balanced, and the second piston 38 is subjected to the elastic force of the elastic member 386. At this time, the elastic member 386 pushes the second piston 38 to move rightward until pushing the second piston 38 to the sixth position to re-shut off the communication between the pressure relief hole 19 and the fluid intake hole 32.

Similarly, a second clamp spring 385 is further disposed on the second piston 38. The second clamp spring 385. The first clamp spring 385 is capable of fixing the first piston 38 in the sixth position after the second piston 38 reaches the sixth position, preventing the second piston 38 from continuing to move in the axial direction.

At this time, as the first piston 35 and the second piston 38 are re-fixed, the communication between the piston chamber 30 and the packing and the pressure release hole 19 is simultaneously cut off, thereby preventing the packing from being secondarily inflated, and the entire setting process of the permanently expanded open hole packer 100 is completed.

As shown in fig. 2, in a preferred embodiment. The outer wall of the outer cylinder 10 is further provided with a balance hole 40 communicating the second gap 384 with the space outside the outer cylinder 10. The balance hole 40 can ensure the pressure balance between the second gap 384 and the space outside the outer cylinder 10, preventing the formation of a local high pressure in the second gap 384 when the second piston 38 moves, and preventing the normal movement of the second piston 38.

The permanently expanded open hole packer 100 of the present invention is used to connect between tubing downhole and run into the well with the tubing. When an open hole staged fracturing operation is performed, and it is desired to isolate the well, a high pressure fluid is first injected into the well, and then the fluid passes through the downhole tubing, the first passage 25 and the fluid intake port 32 in sequence into the first gap 36 of the piston chamber 30.

When fluid enters the first gap 36, the first shear pin 351 is sheared first, and the first piston 35 is pushed to move from a first position for cutting off communication between the rubber cylinder and the liquid inlet 32 to a second position for keeping communication between the rubber cylinder and the liquid inlet 32. And then high-pressure fluid enters the rubber cylinder to support the rubber cylinder to realize setting.

When the packing is set, the first gap 36 is no longer available for high pressure fluid to enter the packing. At this time, the liquid pressure in the first gap 36 will continue to rise until the high-pressure fluid cuts off the second shear pin 381, pushing the second piston 38 to move leftwards until the second piston 38 reaches the fourth position communicating the pressure release hole 19 and the liquid inlet 32. Subsequently, fluid in the piston chamber 30 will be discharged from the relief bore 19, such that the pressure in the first gap 36 is reduced.

As the pressure in the first gap 36 decreases, the pressure on the right side of the first piston 35 will be higher than the pressure on the left side. At this time, the first piston 35 moves leftwards again under the action of the pressure difference until the first piston 35 reaches a fifth position in which the communication between the seat hole 16 and the liquid inlet 32 is re-cut off, and then the first clamp spring 351 fixes the first piston 35 at the fifth position.

When the first piston 35 is fixed, the pressure on both sides of the second piston 38 is balanced as the fluid in the piston chamber 30 is normally discharged from the pressure release hole 19.

When the fluid pressure on both sides of the second piston 38 is balanced, the elastic member 386 pushes the second piston to move rightward until the second clamp spring 385 fixes the second piston 38. At this time, the second piston 38 is in a sixth position that cuts off communication between the relief hole 19 and the intake hole 32.

After the second piston 38 is in the position to shut off communication between the pressure relief bore 19 and the fluid intake bore 32, the entire setting process of the permanently expanded open hole packer 100 is completed.

Finally, it should be noted that the above description is only of a preferred embodiment of the invention and is not to be construed as limiting the invention in any way. Although the invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the techniques described in the foregoing examples, or equivalents may be substituted for elements thereof. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A permanently expanded open hole packer (100), comprising:

an outer cylinder (10) and an inner cylinder (20) which are sleeved together, wherein the outer cylinder is provided with an inner cavity (15), and a first channel (25) for fluid circulation is defined in the inner cylinder;

a piston cavity (30) arranged between the outer cylinder body and the inner cylinder body, a first piston (35) arranged in the piston cavity, a liquid inlet hole (32) arranged on the outer wall of the inner cylinder body and communicated with the first channel and the piston cavity,

a rubber cylinder which is arranged on the outer cylinder body at one end of the piston far away from the liquid inlet and is communicated with the inner cavity,

the first piston is provided with a liquid injection channel (16) which can be communicated with the inner cavity of the rubber cylinder and the liquid inlet, and the first piston can move in the piston cavity under the action of fluid pressure in the first channel, so that the first piston can move from a first position for cutting off communication between the rubber cylinder and the liquid inlet to a second position for keeping the rubber cylinder and the liquid inlet unblocked, and fluid in the first channel flows into the rubber cylinder to realize rubber cylinder setting.

2. The permanently expanded open hole packer (100) of claim 1, wherein the fluid injection passage is configured in a generally "L" shape having a fluid inlet section (161) axially disposed along the outer barrel and a fluid outlet section (162) radially disposed along the outer barrel, the fluid inlet section and fluid outlet section being capable of communicating with the fluid inlet bore (32) and the packing element lumen, respectively.

3. The permanently expanded open hole packer (100) according to claim 2, characterized in that a first step (18) is provided on the inner wall of the piston chamber, which divides the piston chamber into a smaller diameter chamber (181) of smaller diameter and a larger diameter chamber (182) of larger diameter, the chamber diameter of the smaller diameter chamber being set equal to the outer diameter of the first piston,

4. A permanently expandable open hole packer (100) according to any of claims 1-3, further comprising a pressure relief assembly (1) capable of relieving the fluid pressure in the first passage to which the first piston is subjected after the packing is set, such that the first piston is moved from the second position in a direction approaching the first position.

5. The permanently expanded open hole packer (100) of claim 4, wherein the pressure relief assembly comprises a second piston (38) disposed within the piston chamber and a pressure relief bore (19) extending through the outer cylinder to communicate the piston chamber with a space outside the outer cylinder,

wherein a first gap (36) is formed between the second piston and the first piston in communication with the inlet port, the second piston being movable within the piston chamber under fluid pressure within the first passage such that the second piston has a third position in which communication between the pressure relief port and the inlet port is blocked and a fourth position in which communication between the inlet port and the pressure relief port is maintained.

6. The permanently expanded open hole packer (100) of claim 5, wherein the first and second pistons are secured within the piston cavity by first and second shear pins (351, 381), respectively, the shear force of the second shear pin being set to be greater than the shear force of the first shear pin.

7. A permanently expandable open hole packer (100) according to any of claims 1-3, characterized in that a first clamp spring (355) is further provided on the first piston, which first clamp spring is capable of fixing the first piston in a fifth position cutting off the communication between the inlet bore and the setting bore after setting of the packing element.

8. The permanently expanded open hole packer (100) of claim 7, wherein a second gap (384) is provided between the second piston and a sidewall of the piston chamber, an elastic member (386) is provided in the gap, the second piston and the sidewall of the piston chamber are connected by the elastic member,

the elastic piece can push the second piston to move to a sixth position for cutting off communication between the pressure relief hole and the liquid inlet hole when the first piston is in the fifth position.

9. The permanently expanded open hole packer (100) of any one of claims 1-3, further comprising a second clamp spring (385) configured to secure the second piston in a sixth position.

10. A permanently expanding open hole packer (100) according to any of claims 1-3, further provided with a balancing hole (40) on the outer wall of the outer cylinder communicating the second gap with the outer space of the outer cylinder.

11. A permanently expanding open hole packer according to any of claims 1-3, characterised in that a second step (26) is also provided on the outer wall of the inner cylinder on the side of the first piston remote from the inlet opening.